Curved catheter

ABSTRACT

Apparatus and methods are described including inserting a catheter into a subject&#39;s body via a vein of the subject&#39;s groin. The catheter is advanced distally such that a distal end of the catheter is disposed inside the subject&#39;s renal vein. Respective stabilizing portions of the catheter stabilize the catheter by being in contact with inner walls of, respectively, an iliac vein of the subject, and a vena cava of the subject. Subsequently, a medical device is deployed inside the renal vein by retracting the distal end of the catheter, such that the distal end of the catheter is in a retracted state, in which the respective stabilizing portions of the catheter still stabilize the catheter by being in contact with the inner walls of, respectively, the subject&#39;s iliac vein and the subject&#39;s vena cava. Other applications are also described.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional PatentApplication 61/914,470 to Tuval, filed Dec. 11, 2013, entitled “Curvedcatheter.”

The present application is related to:

U.S. patent application Ser. No. 14/405,144 to Tuval, which is the USNational Phase of International Patent Application PCT/IL2013/050495 toTuval (published as WO 13/183060), filed Jun. 6, 2013, entitled“Prosthetic renal valve,” which claims priority from U.S. ProvisionalPatent Application 61/656,244 to Tuval, filed Jun. 6, 2012, entitled“Prosthetic renal valve;” and

International Patent Application PCT/IL2014/050289 to Schwammenthal(published as WO 14/141284), filed Mar. 13, 2014, entitled “Renal pump,”which claims priority from (a) U.S. Provisional Patent Application61/779,803 to Schwammenthal, filed Mar. 13, 2013, entitled “Renal pump,”and (b) US Provisional Patent Application 61/914,475 to Schwammenthal,filed Dec. 11, 2013, entitled “Renal pump.”

All of the above-listed applications are incorporated herein byreference.

FIELD OF EMBODIMENTS OF THE INVENTION

Some applications of the present invention generally relate to medicalapparatus. Specifically, some applications of the present inventionrelate to apparatus and methods associated with placing a medical devicein one or more of a subject's renal vessels.

BACKGROUND

Catheters are medical tools that are used for cardiovascular,urological, gastrointestinal, neurovascular, and ophthalmicapplications. Catheters may be inserted blood vessels, such as toprovide access to the blood vessel to medical devices or tools.Catheters are typically flexible tubes that are inserted into apatient's body via an access port and advanced, over a guidewire, to adesired location inside the subject's body.

SUMMARY OF EMBODIMENTS

In accordance with some applications of the present invention, acatheter is placed into a renal vessel of a subject by being insertedinto the subject's vasculature via a vessel of the subject's groin. Thecatheter defines a continuous tube that defines a lumen therethrough,and a medical device is inserted into the subject's body via thecatheter lumen. The continuous tube defined by the catheter typicallydefines at least a first portion, a second portion, a third portion, afourth portion, and a fifth portion thereof, each of the portions of thecatheter typically defining a shape having given characteristics.

The catheter is typically shaped such that both (a) when the catheter isplaced into a renal vessel that is ipsilateral with respect to thevessel of the groin via which the catheter is inserted, and (b) when thecatheter is placed into a renal vessel that is contralateral withrespect to the vessel of the groin via which the catheter is inserted,the catheter is stabilized by portions of the catheter contacting innerwalls of the blood vessels of the subject at at least two points.Typically, one of the portions of the catheter stabilizes the catheterby contacting an inner wall of an iliac vessel of the subject, andanother one of the portions of the catheter stabilizes the catheter bycontacting an inner wall of the vena cava, or the aorta of the subject.Further typically, the catheter is stabilized by portions of thecatheter contacting inner walls of the blood vessels of the subject atthe at least two points (a) before the catheter is retracted such as torelease the device from the distal end of the catheter, and (b)subsequent to the catheter having been retracted, such as to release thedevice from the distal end of the catheter.

There is therefore provided, in accordance with some applications of thepresent invention, apparatus including:

a medical device that is configured to be inserted into a body of asubject; and

a catheter that defines a continuous tube that defines a lumentherethrough, the medical device being configured to be inserted intothe subject's body via the catheter, the continuous tube including atleast first, second, third, fourth, and fifth portions thereof,

the first portion being disposed at a first end of the catheter andbeing shaped, when the catheter is in a non-constrained configuration,to define a cylindrical portion of the tube that defines a generallystraight central longitudinal axis;

the second portion being disposed adjacent to the first portion andbeing shaped, when the catheter is in the non-constrained configuration,to define a curved cylindrical portion of the tube, a curvature of thesecond portion being such that a central longitudinal axis of the secondportion defines a curve that is concave in a given direction, and thatcurves outwardly away from the central longitudinal axis of the firstportion;

the third portion being disposed between the second and the fourthportions and being shaped, when the catheter is in the non-constrainedconfiguration, to define a curved cylindrical portion of the tube, acurvature of the third portion being such that a central longitudinalaxis of the third portion defines a curve that is convex in the givendirection, and that curves inwardly toward the central longitudinal axisof the first portion, such that the central longitudinal axis of thethird portion meets the central longitudinal axis of the first portion,

the fourth portion being disposed between the third and the fifthportions of the tube, and being shaped, when the catheter is in thenon-constrained configuration, to define a curved cylindrical tube, acurvature of the fourth portion being such that a central longitudinalaxis of the fourth portion defines a curve that is concave in the givendirection, and that curves away from the central longitudinal axis ofthe first portion,

the fifth portion being disposed at a second end of the catheter thefifth portion being shaped, when the catheter is in the non-constrainedconfiguration, to define a curved cylindrical tube, a curvature of thefifth portion being such that a central longitudinal axis of the fifthportion defines a curve that is concave in the given direction, and thatcurves inwardly toward the central longitudinal axis of the firstportion.

For some applications, the continuous tube defined by the catheterfurther includes a sixth portion disposed between the second and thirdportions of the tube, the sixth portion of the tube defining acylindrical portion of the tube that defines a generally straightcentral longitudinal axis, when the catheter is in the non-constrainedconfiguration.

For some applications, a flexibility of at least a distal tip of thefifth portion is greater than a flexibility of each of the first,second, third, and fourth portions.

For some applications, at least a tip of the fifth portion isatraumatic.

For some applications, when the catheter is in the non-constrainedconfiguration, a radius of curvature of the second portion is greaterthan 50 mm. For some applications, when the catheter is in thenon-constrained configuration, the radius of curvature of the secondportion is less than 250 mm.

For some applications, when the catheter is in the non-constrainedconfiguration, a radius of curvature of the third portion is greaterthan 20 mm. For some applications, when the catheter is in thenon-constrained configuration, the radius of curvature of the thirdportion is less than 100 mm.

For some applications, when the catheter is in the non-constrainedconfiguration, a radius of curvature of the fourth portion is greaterthan 10 mm. For some applications, when the catheter is in thenon-constrained configuration, the radius of curvature of the fourthportion is less than 80 mm.

For some applications, when the catheter is in the non-constrainedconfiguration, a radius of curvature of the fifth portion is greaterthan 50 mm. For some applications, when the catheter is in thenon-constrained configuration, the radius of curvature of the fifthportion is less than 250 mm.

For some applications, when the catheter is in the non-constrainedconfiguration, a ratio of a radius of curvature of the second portion toa radius of curvature of the third portion is greater than 1.5:1. Forsome applications, when the catheter is in the non-constrainedconfiguration, the ratio of the radius of curvature of the secondportion to the radius of curvature of the third portion is less than4:1.

For some applications, when the catheter is in the non-constrainedconfiguration, a length of the second portion of the tube, measuredalong the longitudinal axis of the second portion, is at least twice thelength of the medical device. For some applications, the length of thesecond portion of the tube is at least 3 times the length of the medicaldevice.

For some applications, a length of the third portion of the tube,measured along the longitudinal axis of the third portion, is at leasttwice the length of the medical device. For some applications, thelength of the third portion of the tube is at least 3 times the lengthof the medical device.

For some applications, when the catheter is in the non-constrainedconfiguration a length of the second portion, measured along thelongitudinal axis of the second portion, is greater than 20 mm. For someapplications, when the catheter is in the non-constrained configuration,the length of the second portion is less than 50 mm.

For some applications, when the catheter is in the non-constrainedconfiguration, a length of the third portion, measured along thelongitudinal axis of the third portion, is greater than 40 mm. For someapplications, when the catheter is in the non-constrained configuration,the length of the third portion is less than 100 mm.

For some applications, when the catheter is in the non-constrainedconfiguration, a length of the fourth portion, measured along thelongitudinal axis of the fourth portion, is greater than 20 mm. For someapplications, when the catheter is in the non-constrained configuration,the length of the fourth portion is less than 50 mm.

For some applications, when the catheter is in the non-constrainedconfiguration, a length of the fifth portion, measured along thelongitudinal axis of the fifth portion, is greater than 20 mm. For someapplications, when the catheter is in the non-constrained configuration,the length of the fifth portion is less than 50 mm.

For some applications:

the catheter is configured to be:

-   -   inserted into the subject's body via a blood vessel of a groin        of the subject, and    -   advanced distally such that the fifth portion of the catheter is        inserted into a renal vessel that is contralateral to the blood        vessel of the subject's groin; and

the medical device is configured to be deployed inside the contralateralrenal vessel by the catheter being retracted proximally, subsequent toinsertion of the fifth portion of the catheter into the contralateralrenal vessel.

For some applications, when the fifth portion of the catheter isdisposed inside the renal vessel and prior to deploying the medicaldevice by the catheter being retracted proximally, the second portion isconfigured to stabilize the catheter by contacting an inner wall of aniliac vessel of the subject.

For some applications, when the fifth portion of the catheter isdisposed inside the renal vessel, and prior to deploying the medicaldevice by the catheter being retracted proximally, the third portion isconfigured to stabilize the catheter by contacting an inner wall of avessel of the subject selected from the group consisting of: a vena cavaof the subject, and an aorta of the subject.

For some applications, when the fifth portion of the catheter isdisposed inside the renal vessel, and prior to deploying the medicaldevice by the catheter being retracted proximally, the fourth portion isconfigured to stabilize the catheter by contacting an inner wall of therenal vessel.

For some applications, subsequent to deployment of the device in thecontralateral renal vessel by the catheter having been retractedproximally, the second portion is configured to stabilize the catheterby contacting an inner wall of an iliac vessel of the subject.

For some applications, subsequent to deployment of the device in thecontralateral renal vessel by the catheter having been retractedproximally, the third portion is configured to stabilize the catheter bycontacting an inner wall of a vessel of the subject selected from thegroup consisting of: a vena cava of the subject, and an aorta of thesubject.

For some applications, subsequent to deployment of the device in thecontralateral renal vessel by the catheter having been retractedproximally, the fourth portion is configured to stabilize the catheterby contacting an inner wall of the renal vessel.

For some applications:

the catheter is configured to be:

-   -   inserted into the subject's body via a blood vessel of a groin        of the subject, and    -   advanced distally such that the fifth portion of the catheter is        inserted into a renal vessel that is ipsilateral to the blood        vessel of the subject's groin; and

the medical device is configured to be deployed inside the contralateralrenal vessel by the catheter being retracted proximally, subsequent toinsertion of the fifth portion of the catheter into the ipsilateralrenal vessel.

For some applications, when the fifth portion of the catheter isdisposed inside the renal vessel, and prior to deploying the medicaldevice by the catheter being retracted proximally, the second portion isconfigured to stabilize the catheter by contacting an inner wall of aniliac vessel of the subject.

For some applications, when the fifth portion of the catheter isdisposed inside the renal vessel, and prior to deploying the medicaldevice by the catheter being retracted proximally, the third portion isconfigured to stabilize the catheter by contacting an inner wall of avessel of the subject selected from the group consisting of: a vena cavaof the subject, and an aorta of the subject.

For some applications, when the fifth portion of the catheter isdisposed inside the renal vessel, and prior to deploying the medicaldevice by the catheter being retracted proximally, the fourth portion isconfigured to stabilize the catheter by contacting an inner wall of therenal vessel.

For some applications, subsequent to deployment of the device in theipsilateral renal vessel by the catheter having been retractedproximally, the second portion is configured to stabilize the catheterby contacting an inner wall of an iliac vessel of the subject.

For some applications, subsequent to deployment of the device in theipsilateral renal vessel by the catheter having been retractedproximally, the third portion is configured to stabilize the catheter bycontacting an inner wall of a vessel of the subject selected from thegroup consisting of: a vena cava of the subject, and an aorta of thesubject.

For some applications, subsequent to deployment of the device in theipsilateral renal vessel by the catheter having been retractedproximally, the fourth portion is configured to stabilize the catheterby contacting an inner wall of the renal vessel.

For some applications, in the non-constrained configuration of thecatheter, the catheter defines a span in a direction that isperpendicular to the longitudinal axis of the first portion that isgreater than 20 mm.

For some applications, in the non-constrained configuration of thecatheter, the catheter defines a span in the direction that isperpendicular to the longitudinal axis of the first portion that isgreater than 40 mm.

For some applications, in the non-constrained configuration of thecatheter, the catheter defines a span in the direction that isperpendicular to the longitudinal axis of the first portion that is lessthan 70 mm.

For some applications, in the non-constrained configuration of thecatheter, the catheter defines a span in the direction that isperpendicular to the longitudinal axis of the first portion that is lessthan 60 mm.

For some applications, in the non-constrained configuration of thecatheter, the catheter defines a length measured along the longitudinalaxis of the first portion, from a location at which the longitudinalaxis of the second portion begins to curve away from the longitudinalaxis of the first portion until the longitudinal axis of the thirdportion meets the longitudinal axis of the first portion that is greaterthan 80 mm. For some applications, the length is greater than 100 mm.For some applications, the length is less than 250 mm. For someapplications, the length is less than 150 mm.

For some applications, the medical device includes a radially-expandableimpeller disposed inside a radially-expandable cage.

For some applications, a length of cage, measured along a longitudinalaxis of the cage, when the cage is in a radially expanded configuration,is between 17 mm and 26 mm.

There is further provided, in accordance with some applications of thepresent invention, a method including:

inserting a catheter into a body of a subject via a vein of a groin ofthe subject, and

advancing the catheter distally such that:

-   -   a distal end of the catheter is disposed inside a renal vein of        the subject, and    -   respective stabilizing portions of the catheter stabilize the        catheter by being in contact with inner walls of, respectively,        an iliac vein of the subject, and a vena cava of the subject;        and

subsequently, deploying a medical device inside the renal vein byretracting the distal end of the catheter, such that the distal end ofthe catheter is in a retracted state, in which the respectivestabilizing portions of the catheter still stabilize the catheter bybeing in contact with the inner walls of, respectively, the subject'siliac vein and the subject's vena cava.

For some applications, advancing the catheter distally includesadvancing the catheter distally such that a further stabilizing portionof the catheter stabilizes the catheter by being in contact with aninner wall of the renal vein.

For some applications, retracting the distal end of the catheterincludes retracting the distal end of the catheter, such that while thedistal end of the catheter is in its retracted state, a furtherstabilizing portion of the catheter stabilizes the catheter by being incontact with an inner wall of the renal vein.

For some applications, advancing the catheter distally such that thedistal end of the catheter is disposed inside the subject's renal veinincludes advancing the catheter distally such that the distal end of thecatheter is disposed inside a renal vein of the subject that iscontralateral to the vein of the subject's groin via which the catheteris inserted.

For some applications, advancing the catheter distally such that thedistal end of the catheter is disposed inside the subject's renal veinincludes advancing the catheter distally such that the distal end of thecatheter is disposed inside a renal vein of the subject that isipsilateral to the vein of the subject's groin via which the catheter isinserted.

For some applications, the method further includes operating the medicaldevice, inside the renal vein, while the catheter is disposed inside abody of the subject in its retracted state, such that the cathetersupports the medical device during its operation.

For some applications, deploying the device includes deploying aradially-expandable impeller that is disposed inside aradially-expandable impeller cage, and operating the medical deviceincludes rotating the impeller.

There is further provided, in accordance with some applications of thepresent invention, a method including:

inserting a catheter into a body of a subject via an artery of a groinof the subject, and

advancing the catheter distally such that:

-   -   a distal end of the catheter is disposed inside a renal artery        of the subject, and    -   respective stabilizing portions of the catheter stabilize the        catheter by being in contact with inner walls of, respectively,        an iliac artery of the subject, and an aorta of the subject; and

subsequently, deploying a medical device inside the renal artery byretracting the distal end of the catheter, such that the distal end ofthe catheter is in a retracted state, in which the respectivestabilizing portions of the catheter still stabilize the catheter bybeing in contact with the inner walls of, respectively, the subject'siliac artery and the subject's aorta.

For some applications, advancing the catheter distally includesadvancing the catheter distally such that a further stabilizing portionof the catheter stabilizes the catheter by being in contact with aninner wall of the renal artery.

For some applications, retracting the distal end of the catheterincludes retracting the distal end of the catheter, such that while thedistal end of the catheter is in its retracted state, a furtherstabilizing portion of the catheter stabilizes the catheter by being incontact with an inner wall of the renal artery.

For some applications, advancing the catheter distally such that thedistal end of the catheter is disposed inside the subject's renal arteryincludes advancing the catheter distally such that the distal end of thecatheter is disposed inside a renal artery of the subject that iscontralateral to the artery of the subject's groin via which thecatheter is inserted.

For some applications, advancing the catheter distally such that thedistal end of the catheter is disposed inside the subject's renal arteryincludes advancing the catheter distally such that the distal end of thecatheter is disposed inside a renal artery of the subject that isipsilateral to the artery of the subject's groin via which the catheteris inserted.

For some applications, the method further includes operating the medicaldevice, inside the renal artery, while the catheter is disposed inside abody of the subject in its retracted state, such that the cathetersupports the medical device during its operation.

For some applications, deploying the device includes deploying aradially-expandable impeller that is disposed inside aradially-expandable impeller cage, and operating the medical deviceincludes rotating the impeller.

The present invention will be more fully understood from the followingdetailed description of embodiments thereof, taken together with thedrawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a catheter, in accordance withsome applications of the present invention;

FIGS. 2A-B are schematic illustrations of the catheter being insertedvia a vein of a subject's groin, a distal end of the catheter beingplaced into a renal vein of the subject that is ipsilateral to the veinof the groin, in accordance with some applications of the presentinvention;

FIGS. 2C-D are schematic illustrations of portions of the catheter,respectively before and after a medical device has been deployed insidethe ipsilateral renal vein, via the distal end of the catheter, inaccordance with some applications of the present invention;

FIG. 2E is a schematic illustration of a catheter that has beeninserted, via an artery of a subject's groin, such that a distal end ofthe catheter is placed into a renal artery of the subject that isipsilateral to the artery of the groin, in accordance with someapplications of the present invention;

FIGS. 3A-B are schematic illustrations of a catheter being inserted viaa vein of a subject's groin, a distal end of the catheter being placedinto a renal vein of the subject that is contralateral to the vein ofthe groin, in accordance with some applications of the presentinvention;

FIGS. 3C-D are schematic illustrations of portions of the catheter,respectively before and after a medical device has been deployed insidethe contralateral renal vein, via the distal end of the catheter, inaccordance with some applications of the present invention; and

FIG. 3E is a schematic illustration of a catheter that has beeninserted, via an artery of a subject's groin, such that a distal end ofthe catheter is placed into a renal artery of the subject that iscontralateral to the artery of the groin, in accordance with someapplications of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Reference is now made to FIG. 1, which is a schematic illustration of acatheter 20, in accordance with some applications of the presentinvention. Catheter 20 defines a continuous tube that defines a lumentherethrough. A medical device 50 (FIG. 2D) is typically inserted intothe subject's body via the catheter lumen. The continuous tube definedby catheter 20 typically defines at least a first portion 22, a secondportion 24, a third portion 26, a fourth portion 28, and a fifth portion30 thereof. For some applications, the continuous tube additionallydefines a sixth portion 32 having characteristics as describedhereinbelow. Alternatively or additionally, the continuous tube definesone or more different additional portions.

Typically, in a non-constrained configuration of the catheter (i.e., inthe absence of any force being applied to the catheter), each of theportions of the catheter defines a shape having characteristics asdescribed hereinbelow. For some applications, the catheter is made froma polymer, a polymer that is reinforced with a braided or coiled metalor alloy, a metal, and/or an alloy (such as nitinol). The catheter isshape set (e.g., by shape setting the catheter in a mold, by steamshaping, and/or by mechanical shape setting), such that the shape ofeach of the portions has the described characteristics.

First portion 22 of catheter 20 is disposed at a first, proximal end ofthe catheter. When the catheter is in the non-constrained configuration,the first portion typically defines a cylindrical portion of the tubethat defines a generally straight central longitudinal axis 23.

As used in the present application, including in the claims, a “centrallongitudinal axis” of a structure is the set of all centroids ofcross-sectional sections of the structure along the structure. Thus thecross-sectional sections are locally perpendicular to the centrallongitudinal axis, which runs along the structure. (If the structure iscircular in cross-section, the centroids correspond with the centers ofthe circular cross-sectional sections.)

Second portion 24 is typically disposed adjacent to the first portion.When the catheter is in the non-constrained configuration, the secondportion is typically shaped to define a curved cylindrical portion ofthe tube. The curvature of the second portion is such that a centrallongitudinal axis 25 of the second portion defines a curve that isconcave in a given direction, and that curves outwardly away from thecentral longitudinal axis of the first portion. For example, as shown inFIG. 1 the curve is concave in the direction in which arrow 34 ispointing.

For some applications, when the catheter is in the non-constrainedconfiguration, a radius of curvature R2 of second portion 24 is greaterthan 50 mm, and/or less than 250 mm, e.g., 50 mm-250 mm. Typically, alength of the second portion of the tube (measured along centrallongitudinal axis 25 of the second portion) is at least twice the length(e.g., at least 3 times the length) of medical device 50 (FIG. 2D),which is configured to be placed inside the subject's body, via thecatheter. For some applications, when the catheter is in thenon-constrained configuration, the length of the second portion of thetube is greater than 20 mm, and/or less than 50 mm, e.g., 20 mm-50 mm.

Third portion 26 of catheter 20 is disposed between the second and thefourth portions. When the catheter is in the non-constrainedconfiguration, the third portion is shaped to define a curvedcylindrical portion of the tube. The curvature of the third portion istypically such that a central longitudinal axis 27 of the third portiondefines a curve that is convex in the given direction (in the exampleshown, in the direction of arrow 34), and that curves inwardly towardthe central longitudinal axis of the first portion. Further typically,the curvature of the third portion is such that the central longitudinalaxis of the third portion meets central longitudinal axis 23 of thefirst portion. For example, as shown in FIG. 1, central longitudinalaxis 27 of the third portion meets central longitudinal axis 23 of thefirst portion at point 36.

For some applications, when the catheter is in the non-constrainedconfiguration, a radius of curvature R3 of third portion 26 is greaterthan 20 mm, and/or less than 100 mm, e.g., 20 mm-100 mm. For someapplications, when the catheter is in the non-constrained configuration,a ratio of radius of curvature R2 of the second portion to radius ofcurvature R3 of the third portion is greater than 1.5:1, and/or lessthan 4:1, e.g., 1.5:1-4:1.

Typically, a length of the third portion of the tube (measured alongcentral longitudinal axis 27 of the third portion) is at least twice thelength (e.g., at least 3 times the length) of medical device 50 (FIG.2D), which is configured to be placed inside the subject's body, viacatheter 20. For some applications, when the catheter is in thenon-constrained configuration, the length of the third portion of thetube is greater than 40 mm, and/or less than 100 mm, e.g., 40 mm-100 mm.

Fourth portion 28 is disposed between the third and the fifth portionsof the tube. When the catheter is in the non-constrained configuration,the fourth portion typically defines a curved cylindrical tube. Thecurvature of the fourth portion is typically such that a centrallongitudinal axis 29 of the fourth portion defines a curve that isconcave in the given direction (in the example shown, in the directionof arrow 34), and that curves away from central longitudinal axis 23 offirst portion 22.

For some applications, when the catheter is in the non-constrainedconfiguration, a radius of curvature R4 of fourth portion 28 is greaterthan 10 mm, and/or less than 80 mm, e.g., 10 mm-80 mm. For someapplications, when the catheter is in the non-constrained configuration,a length of the fourth portion of the tube (measured along centrallongitudinal axis 29 of the fourth portion) is greater than 20 mm,and/or less than 50 mm, e.g., 20 mm-50 mm.

Fifth portion 30 is disposed at a second end of the catheter. When thecatheter is in the non-constrained configuration, the fifth portion istypically shaped to define a curved cylindrical tube. The curvature ofthe fifth portion is typically such that a central longitudinal axis 31of the fifth portion defines a curve that is concave in the givendirection (in the example shown, in the direction of arrow 34), and thatcurves inwardly toward central longitudinal axis 23 of first portion 22.For some applications, at least a distal tip 37 of the fifth portion ofthe continuous tube defined by the catheter is greater than aflexibility of each of the first, second, third, and fourth portions.

For some applications, when the catheter is in the non-constrainedconfiguration, a radius of curvature R5 of fifth portion 30 is greaterthan 50 mm, and/or less than 250 mm, e.g., 50 mm-250 mm. For someapplications, when the catheter is in the non-constrained configuration,a length of the fifth portion of the tube (measured along centrallongitudinal axis 31 of the fifth portion) is greater than 20 mm, and/orless than 50 mm, e.g., 20 mm-50 mm.

As described hereinabove, for some applications, the tube defined bycatheter 20 further defines a sixth portion 32, disposed between thesecond and third portions of the tube. For some applications, when thecatheter is in the non-constrained configuration, the sixth portion ofthe tube defines a cylindrical portion of the tube that defines agenerally straight central longitudinal axis. For some applications, alength of the sixth portion (measured along the central longitudinalaxis of the sixth portion) is greater than 10 mm, and/or less than 100mm, e.g., 10 mm-100 mm.

Typically, in the non-constrained configuration of the catheter (i.e.,in the absence of any force being applied to the catheter), the catheterdefines a span SP in a direction that is perpendicular to longitudinalaxis 23 of first portion 22 that is greater than 20 mm (e.g., greaterthan 40 mm), and/or less than 70 mm (e.g., less than 60 mm), e.g., 20mm-70 mm (e.g., 40 mm to 60 mm). Further typically, in thenon-constrained configuration of the catheter (i.e., in the absence ofany force being applied to the catheter), the catheter defines a lengthL1, measured along longitudinal axis 23 of first portion 22, from wherethe second catheter begins to curve until point 36 at which longitudinalaxis 27 of third portion 26 meets longitudinal axis 23 of first portion22 that is greater than 80 mm (e.g., greater than 100 mm), and/or lessthan 250 mm (e.g., less than 150 mm), e.g., 80 mm-250 mm (e.g., 100 mmto 150 mm). Typically, when the fifth portion of the catheter is placedinside a renal vessel of the subject, as described hereinbelow, lengthL1 corresponds to the distance from where the second portion of thecatheter contacts the wall of an iliac vessel, until the renal vessel.

Reference is now made to FIGS. 2A-B, which are schematic illustrationsof catheter 20 being inserted into the subject's vasculature via a veinof a subject's groin (right femoral vein 40, in the example shown). Adistal end of the catheter is advanced into a renal vein of the subjectthat is ipsilateral to the vein of the groin (e.g., right renal vein 42,in the example shown), in accordance with some applications of thepresent invention. For some applications, in order to insert the distalend of the catheter into the renal vein, the distal end of the catheteris first placed into the subject's vena cava 44, downstream of (i.e.,distal to) the renal vein. The catheter is inserted such that due to thecurvature of the catheter, the distal tip of the catheter pushes againstthe inner wall of the vena cava on the ipsilateral side of the venacava, as shown in FIG. 2A. The catheter is then retracted proximally,such that when the distal tip of the catheter passes the opening to therenal vein, the distal tip of the catheter enters the renal vein. Whenthe distal tip has entered the renal vein, the catheter is thenadvanced, such that the distal tip of the catheter is disposed insidethe renal vein in the vicinity of the subject's kidney 46, as shown inFIG. 2B.

As described hereinabove, typically, at least distal tip 37 of the fifthportion of the continuous tube defined by catheter 20 (i.e. the distaltip of the catheter) is greater than a flexibility of each of the first,second, third, and fourth portions of the catheter. For someapplications, the distal tip of the fifth portion (i.e. the distal tipof the catheter) is thus configured to be atraumatic. For someapplications, the tip being atraumatic reduces a likelihood of an injurybeing caused to the inner wall of the vena cava, during the insertion ofthe catheter, relative to if the distal tip of the catheter were notatraumatic. For some applications, the distal tip of the catheter ismade of a more flexible material (e.g., a more flexible polymer) thanthat of the remainder of the catheter, and/or a reinforcing material(e.g., a braided or coiled metal or alloy) that reinforces the remainderof the catheter is not present in the distal tip of the catheter, or ismade to be more flexible in the distal tip of the catheter.

For some applications, a control unit 48 disposed outside the subject'sbody is coupled to medical device 50 (FIG. 2D), and is configured tocontrol the functioning of the medical device. For example, the medicaldevice may be a pump, and the control unit may control the functioningof the pump, by rotating a portion of the pump via a motor 49.Typically, the control unit includes any type of processor (such as acomputer processor) configured to execute the actions described herein.Further typically, a user interacts with the control unit via a userinterface 51, which typically includes any type of user interfaceconfigured to receive inputs from a user and/or to provide outputs tothe user (including but not limited to keyboards, displays, pointingdevices, etc.).

Reference is now made to FIGS. 2C-D, which are schematic illustrationsof portions of catheter 20, respectively before and after a medicaldevice 50 has been deployed inside renal vein 42, via the distal end ofthe catheter, in accordance with some applications of the presentinvention. Typically, medical device 50 is self expandable. For example,medical device 50 may be a self expandable valve, a self expandablestent, and/or a self-expandable pump. For some applications, medicaldevice 50 is a blood pump that includes a radially-expandable impellerdisposed inside a radially-expandable impeller cage, e.g., as describedwith reference to 12Ai-22Cii of WO 14/141284 to Schwammenthal, which isincorporated herein by reference. For such applications, control unit 48typically controls the functioning of the pump, by rotating the impellerof the pump via motor 49. Typically, the medical device is deployedinside the renal vein by retracting the distal end of catheter 20, suchthat the medical device self expands, as shown in the transition fromFIG. 2C to FIG. 2D.

Typically, during deployment of medical device 50 inside renal vein(i.e., during retraction of catheter 20 from the position shown in FIG.2C to the position shown in FIG. 2D), second portion 24 of the catheteris configured to stabilize the catheter by contacting an inner wall ofan iliac vein 52 of the subject. Further typically, subsequent to thedeployment of the medical device inside the renal vein, second portion24 of the catheter is configured to stabilize the catheter by contactingthe inner wall of iliac vein 52, as shown in FIG. 2D. In this manner,second portion 24 acts as a stabilizing portion of the catheter. Forsome applications, the device is temporarily placed inside the subject'srenal vein, in order to provide an acute treatment to the subject. Thecatheter remains in place inside the subject's vasculature during thetreatment, and the second portion of the catheter provides stabilizationto the catheter by contacting the inner wall of iliac vein 52, as shownin FIG. 2D. Subsequent to the treatment being terminated, device 50 iswithdrawn from the subject's renal vein via the catheter.

As described hereinabove, the length of second portion 24 of the tubedefined by catheter 20 is typically at least twice the length (e.g., atleast 3 times the length) of medical device 50. Typically, the secondportion is thus configured to contact the inner wall of iliac vein 52both (a) before the catheter has been retracted such as to release thedevice from the distal end of the catheter (as shown in FIG. 2C), and(b) subsequent to the catheter having been retracted at least by thelength of the device, such as to release the device from the distal endof the catheter (as shown in FIG. 2D).

As described hereinabove, for some applications, medical device 50 is ablood pump that includes a radially-expandable impeller disposed insidea radially-expandable impeller cage, e.g., as described with referenceto 12Ai-22Cii of WO 14/141284 to Schwammenthal, which is incorporatedherein by reference. For such applications, the length of the cage,measured along the longitudinal axis of the cage, and when the cage isin a radially expanded configuration, is typically greater than 17 mm,less than 26 mm, and/or between 17 and 26 mm. For some applications, thelength of second portion 24 of the tube defined by catheter 20 is atleast 30 mm (e.g., at least 50 mm), and/or less than 80 mm (e.g., lessthan 65 mm).

Typically, during deployment of medical device 50 inside renal vein(i.e., during retraction of catheter 20 from the position shown in FIG.2C to the position shown in FIG. 2D), third portion 26 of the catheteris configured to stabilize the catheter by contacting an inner wall ofthe subject's vena cava 44. Further typically, subsequent to thedeployment of the medical device inside the renal vein, third portion 26of the catheter is configured to stabilize the catheter by contactingthe inner wall of the vena cava, as shown in FIG. 2D. In this manner,third portion 26 acts as a stabilizing portion of the catheter. Asdescribed hereinabove, the length of the third portion of the tubedefined by catheter 20 is typically at least twice the length (e.g., atleast 3 times the length) of medical device 50. Typically, the thirdportion is thus configured to contact the inner wall of vena cava 44both (a) before the catheter has been retracted such as to release thedevice from the distal end of the catheter (as shown in FIG. 2C), and(b) subsequent to the catheter having been retracted at least by thelength of the device, such as to release the device from the distal endof the catheter (as shown in FIG. 2D).

As described hereinabove, for some applications, medical device 50 is ablood pump that includes a radially-expandable impeller disposed insidea radially-expandable impeller cage, e.g., as described with referenceto 12Ai-22Cii of WO 14/141284 to Schwammenthal, which is incorporatedherein by reference. For such applications, the length of the cage,measured along the longitudinal axis of the cage, is typically greaterthan 17 mm, less than 26 mm, and/or between 17 and 26 mm. For someapplications, the length of third portion 26 of the tube defined bycatheter 20 is at least 30 mm (e.g., at least 50 mm), and/or less than80 mm (e.g., less than 65 mm).

For some applications, during at least a portion of the deployment ofmedical device 50 inside renal vein 42, fourth portion 28 of thecatheter is configured to stabilize the catheter by contacting an innerwall of the subject's renal vein. For example, as shown in FIG. 2C,prior to the retraction of catheter 20 such as to deploy device 50, thefourth portion stabilizes the catheter by contacting the inner wall ofthe renal vein. In this manner, fourth portion 28 acts as a stabilizingportion of the catheter. For some applications, fourth portion 28 of thecatheter is configured to stabilize the catheter by contacting an innerwall of the subject's renal vein even after the device has been deployedby the catheter having been retracted proximally. Alternatively, fourthportion 28 of the catheter is configured not contact the inner wall ofthe subject's renal vein after the device has been deployed by thecatheter having been retracted proximally, as shown in FIG. 2D.

Reference is now made to FIG. 2E, which is a schematic illustration ofcatheter 20, the catheter having been inserted into the subject'svasculature via an artery of a subject's groin (right femoral artery 60,in the example shown). A distal end of the catheter is advanced into arenal artery of the subject that is ipsilateral to the artery of thegroin (e.g., right renal artery 62, in the example shown). For someapplications, generally similar techniques to those describedhereinabove with reference to FIGS. 2A-2D are performed on the arterialside of the subject's vasculature, mutatis mutandis. For someapplications, when catheter 20 is used on the arterial side of thesubject's vasculature, during at least a portion of the procedure (a)second portion 24 of the catheter stabilizes the catheter by contactingan inner wall of an iliac artery 64 of the subject, (b) third portion 26of the catheter stabilizes the catheter by contacting an inner wall ofan aorta 66 of the subject, and (c) fourth portion 28 of the catheterstabilizes the catheter by contacting an inner wall of renal artery 62.Typically, both before and after the catheter is retracted such as torelease device 50 inside the renal artery, (a) second portion 24 of thecatheter stabilizes the catheter by contacting the inner wall of iliacartery 64, and (b) third portion 26 of the catheter stabilizes thecatheter by contacting the inner wall of aorta 66.

Reference is now made to FIGS. 3A-B, which are schematic illustrationsof catheter 20 being inserted via a vein of a subject's groin (rightfemoral vein 40, in the example shown), a distal end of the catheterbeing advanced into a renal vein of the subject that is contralateral tothe vein of the groin (e.g., left renal vein 72, in the example shown),in accordance with some applications of the present invention.

For some applications, in order to insert the distal end of the catheterinto renal vein 72, the distal end of the catheter is first placed intothe subject's vena cava 44, downstream of (i.e., distal to) the renalvein. The catheter is inserted such that due to the curvature of thecatheter, the distal tip of the catheter pushes against the inner wallof the vena cava on the contralateral side of the vena cava, as shown inFIG. 3A. The catheter is then retracted proximally, such that when thedistal tip of the catheter passes the opening to the renal vein, thedistal tip of the catheter enters the renal vein. When the distal tiphas entered the renal vein, the catheter is then advanced, such that thedistal tip of the catheter is disposed inside the renal vein in thevicinity of the subject's kidney 46, as shown in FIG. 3B. As describedhereinabove with reference to FIGS. 2A-B, typically, the tip of catheter20 being atraumatic reduces a likelihood of an injury being caused tothe inner wall of the vena cava, during the insertion of the catheter,relative to if the distal tip of the catheter were not atraumatic.

Reference is now made to FIGS. 3C-D, which are schematic illustrationsof portions of catheter 20, respectively before and after medical device50 has been deployed inside renal vein 72, via the distal end of thecatheter, in accordance with some applications of the present invention.Typically, during deployment of medical device 50 inside renal vein 72(i.e., during retraction of catheter 20 from the position shown in FIG.3C to the position shown in FIG. 3D), second portion 24 of the catheteris configured to stabilize the catheter by contacting an inner wall ofiliac vein 52. Further typically, subsequent to the deployment of themedical device inside the renal vein second portion 24 of the catheteris configured to stabilize the catheter by contacting the inner wall ofiliac vein 52, as shown in FIG. 3D. As described hereinabove, withreference to FIGS. 2C-D, for some applications, the device istemporarily placed inside the subject's renal vein, in order to providean acute treatment to the subject. The catheter remains in place insidethe subject's vasculature during the treatment, and the second portionof the catheter provides stabilization to the catheter by contacting theinner wall of iliac vein 52, as shown in FIG. 3D. Subsequent to thetreatment being terminated, the device is withdrawn from the subject'srenal vein via the catheter.

As described hereinabove with reference to FIGS. 2C-D, the length of thesecond portion of the tube defined by catheter 20 is typically at leasttwice the length (e.g., at least 3 times the length) of medical device50. Typically, the second portion is thus configured to contact theinner wall of iliac vein 52 both (a) before the catheter has beenretracted such as to release the device from the distal end of thecatheter (as shown in FIG. 3C), and (b) subsequent to the catheterhaving been retracted at least by the length of the device, such as torelease the device from the distal end of the catheter (as shown in FIG.3D).

As described hereinabove, for some applications, medical device 50 is ablood pump that includes a radially-expandable impeller disposed insidea radially-expandable impeller cage, e.g., as described with referenceto 12Ai-22Cii of WO 14/141284 to Schwammenthal, which is incorporatedherein by reference. For such applications, the length of the cage,measured along the longitudinal axis of the cage, is typically greaterthan 17 mm, less than 26 mm, and/or between 17 and 26 mm. For someapplications, the length of second portion 24 of the tube defined bycatheter 20 is at least 30 mm (e.g., at least 50 mm), and/or less than80 mm (e.g., less than 65 mm).

Typically, during deployment of medical device 50 inside renal vein 72(i.e., during retraction of catheter 20 from the position shown in FIG.3C to the position shown in FIG. 3D), third portion 26 of the catheteris configured to stabilize the catheter by contacting an inner wall ofthe subject's vena cava 44. Further typically, subsequent to thedeployment of the medical device inside the renal vein, third portion 26of the catheter is configured to stabilize the catheter by contactingthe inner wall of the vena cava, as shown in FIG. 3D. As describedhereinabove, the length of the third portion of the tube defined bycatheter 20 is typically at least twice the length (e.g., at least 3times the length) of medical device 50. Typically, the third portion isthus configured to contact the inner wall of vena cava 44 both (a)before the catheter has been retracted such as to release the devicefrom the distal end of the catheter (as shown in FIG. 3C), and (b)subsequent to the catheter having been retracted at least by the lengthof the device, such as to release the device from the distal end of thecatheter (as shown in FIG. 3D).

As described hereinabove, for some applications, medical device 50 is ablood pump that includes a radially-expandable impeller disposed insidea radially-expandable impeller cage, e.g., as described with referenceto 12Ai-22Cii of WO 14/141284 to Schwammenthal, which is incorporatedherein by reference. For such applications, the length of the cage,measured along the longitudinal axis of the cage, is typically greaterthan 17 mm, less than 26 mm, and/or between 17 and 26 mm. For someapplications, the length of third portion 26 of the tube defined bycatheter 20 is at least 30 mm (e.g., at least 50 mm), and/or less than80 mm (e.g., less than 65 mm).

For some applications, during at least a portion of the deployment ofmedical device 50 inside renal vein 72, fourth portion 28 of thecatheter is configured to stabilize the catheter by contacting an innerwall of the subject's renal vein. For example, as shown in FIG. 3C,prior to the retraction of catheter 20 such as to deploy device 50, thefourth portion stabilizes the catheter by contacting the inner wall ofthe renal vein. For some applications, fourth portion 28 of the catheteris configured to stabilize the catheter by contacting an inner wall ofthe subject's renal vein even after the device has been deployed by thecatheter having been retracted proximally, as shown in FIG. 3D.

Reference is now made to FIG. 3E, which is a schematic illustration ofcatheter 20, the catheter having been inserted into the subject'svasculature via an artery of a subject's groin (right femoral artery 60,in the example shown). A distal end of the catheter is advanced into arenal artery of the subject that is contralateral to the artery of thegroin (e.g., right renal artery 82, in the example shown). For someapplications, generally similar techniques to those describedhereinabove with reference to FIGS. 3A-3D are performed on the arterialside of the subject's vasculature, mutatis mutandis. For someapplications, when catheter 20 is used on the arterial side of thesubject's vasculature, during at least a portion of the procedure (a)second portion 24 of the catheter stabilizes the catheter by contactingan inner wall of an iliac artery 64 of the subject, (b) third portion 26of the catheter stabilizes the catheter by contacting an inner wall ofan aorta 66 of the subject, and (c) fourth portion 28 of the catheterstabilizes the catheter by contacting an inner wall of renal artery 82.Typically, both before and after the catheter is retracted such as torelease device 50 inside the renal artery, (a) second portion 24 of thecatheter stabilizes the catheter by contacting the inner wall of iliacartery 64, and (b) third portion 26 of the catheter stabilizes thecatheter by contacting the inner wall of aorta 66.

It is noted that, in accordance with the above description of catheter20, the catheter is shaped such that both (a) when the catheter isplaced into a renal vessel that is ipsilateral with respect to thevessel of the groin via which the catheter is inserted, and (b) when thecatheter is placed into a renal vessel that is ipsilateral with respectto the vessel of the groin via which the catheter is inserted, thecatheter is stabilized by portions of the catheter contacting innerwalls of the blood vessels of the subject at at least two points.Typically, the second portion of the catheter stabilizes the catheter bycontacting an inner wall of an iliac vessel of the subject, and thethird portion stabilizes the catheter by contacting an inner of the venacava or the aorta of the subject. Further typically, the catheter isstabilized by portions of the catheter contacting inner walls of theblood vessels of the subject at the at least two points (a) before thecatheter is retracted such as to release the device from the distal endof the catheter, and (b) subsequent to the catheter having beenretracted such as to release the device from the distal end of thecatheter.

It is noted that, for some applications, catheter 20 is used for theinsertion of a medical device therethrough that provides a therapy(e.g., renal denervation) to a renal vessel (e.g., a renal artery or arenal vein). Subsequent to providing the therapy, the device iswithdrawn from the renal vessel via the catheter. Catheter 20 providesstabilization during the advancement of the device, during thewithdrawal of the device, and/or during the provision of the therapy by(a) second portion 24 of the catheter stabilizing the catheter bycontacting an inner wall of an iliac vessel of the subject, (b) thirdportion 26 of the catheter stabilizing the catheter by contacting aninner wall of vena cava 44 or aorta 66 of the subject, and, optionally,(c) fourth portion 28 of the catheter stabilizing the catheter bycontacting an inner wall of the renal vessel, in accordance with thetechniques described hereinabove.

Although catheter 20 is described hereinabove as being inserted via afemoral blood vessel, for some applications, catheter 20 is insertedthrough a different peripheral vessel in the subject's groin, e.g., theiliofemoral vein. Alternatively or additionally, the catheter isinserted via a vein of the arm (e.g., a brachial, or antecubital vein),the chest (e.g., the subclavian vein), or the neck (e.g., the jugularvein). For some applications, catheter 20 is inserted into the hepaticvein.

In general, in the specification and in the claims of the presentapplication, the term “proximal” and related terms, when used withreference to a device or a portion thereof, should be interpreted tomean an end of the device or the portion thereof that, when insertedinto a subject's body, is typically closer to a location through whichthe device is inserted into the subject's body. The term “distal” andrelated terms, when used with reference to a device or a portionthereof, should be interpreted to mean an end of the device or theportion thereof that, when inserted into a subject's body, is typicallyfurther from the location through which the device is inserted into thesubject's body.

It will be appreciated by persons skilled in the art that the presentinvention is not limited to what has been particularly shown anddescribed hereinabove. Rather, the scope of the present inventionincludes both combinations and subcombinations of the various featuresdescribed hereinabove, as well as variations and modifications thereofthat are not in the prior art, which would occur to persons skilled inthe art upon reading the foregoing description.

1.-57. (canceled)
 58. A method comprising: inserting a catheter into abody of a subject via an artery of a groin of the subject, and advancingthe catheter distally such that: a distal end of the catheter isdisposed inside a renal artery of the subject, and respectivestabilizing portions of the catheter stabilize the catheter by being incontact with inner walls of, respectively, an iliac artery of thesubject, and an aorta of the subject; and subsequently, deploying amedical device inside the renal artery by retracting the distal end ofthe catheter, such that the distal end of the catheter is in a retractedstate, in which the respective stabilizing portions of the catheterstill stabilize the catheter by being in contact with the inner wallsof, respectively, the subject's iliac artery and the subject's aorta.59. The method according to claim 58, wherein advancing the catheterdistally comprises advancing the catheter distally such that a furtherstabilizing portion of the catheter stabilizes the catheter by being incontact with an inner wall of the renal artery.
 60. The method accordingto claim 58, wherein retracting the distal end of the catheter comprisesretracting the distal end of the catheter, such that while the distalend of the catheter is in its retracted state, a further stabilizingportion of the catheter stabilizes the catheter by being in contact withan inner wall of the renal artery.
 61. The method according to claim 58,wherein advancing the catheter distally such that the distal end of thecatheter is disposed inside the subject's renal artery comprisesadvancing the catheter distally such that the distal end of the catheteris disposed inside a renal artery of the subject that is contralateralto the artery of the subject's groin via which the catheter is inserted.62. The method according to claim 58, wherein advancing the catheterdistally such that the distal end of the catheter is disposed inside thesubject's renal artery comprises advancing the catheter distally suchthat the distal end of the catheter is disposed inside a renal artery ofthe subject that is ipsilateral to the artery of the subject's groin viawhich the catheter is inserted.
 63. The method according to claim 58,further comprising operating the medical device, inside the renalartery, while the catheter is disposed inside a body of the subject inits retracted state, such that the catheter supports the medical deviceduring its operation.
 64. The method according to claim 63, whereindeploying the device comprises deploying a radially-expandable impellerthat is disposed inside a radially-expandable impeller cage, and whereinoperating the medical device comprises rotating the impeller.